Re: 64 9.5 Sportwin Gear Case
The difference was a model run change. Not sure off hand exactly what changes.
As stated, I believe it would work. IF the drive shaft and shift rod have the same part numbers.
That being said, seems expensive for what you are getting. I would look elsewhere myself. Call the salvage yards, or post a wanted ad at aomci.org.
I would reccomend getting a parts motor. May be able to get one for around the 50 buck range, and then you will have other parts should you need them. Just my suggestion.